Leaving Decagon? Plan your 90-day ISO window
Calculator · free · no signup · pre-IPODecagon is pre-IPO. Left with vested ISOs? Model the 90-day exercise-or-forfeit decision and its AMT cost at any valuation: current 409A or an expected exit price.
Beta · invite-only · AlphaLatitude Inc. · Free Tools
Your grant
Tax inputs
Grant timeline
Recommended exercise quantity
Exercise all 10,000
With 10%/yr expected growth over the 3-yr hold, every share's expected after-tax gain exceeds its marginal AMT cost. Net value: $171,946 at horizon.
Net after-tax value vs. shares exercised
Each point is the expected after-tax NPV at your hold horizon if you exercise that many shares now and let the rest expire.
Year-by-year tax breakdown
You pay the higher of Regular tax and Tentative AMT per jurisdiction, then subtract Credit recovered. The result is Net tax. Hover any number for the bracket-by-bracket breakdown.
| 1 | 10,000 | |||
| 2 | 0 | |||
| 3 | 0 |
Federal AMT credit
Earned
$134,654
Recovered
$29,764
Remaining
$104,890
The AMT credit only recovers in years where regular tax exceeds AMT — typically a year with no ISO exercise. It carries forward indefinitely (Form 8801) and applies in any future tax year where regular tax exceeds AMT.
Estimates only. Excludes disqualifying dispositions, NSOs, multi-state moves, and AMT preferences other than ISO bargain elements. Long-term capital gains tax assumes a qualifying disposition (ISO held ≥1 yr from exercise and ≥2 yr from grant); state LTCG follows ordinary brackets except where the state grants preferential treatment (HI, ND, SC, WI, AR, NM) or has a dedicated LTCG-only tax (WA). Assumes you are within the $100K ISO limit (any portion of an annual ISO grant whose FMV at grant exceeds $100K is treated as NSO from the start, §422(d)). State AMT figures are 2025 (next-year values published in late 2026). Not financial advice.
QSBS note. If your shares qualify (typically pre-IPO C-corp grants held 5+ years), a federal rule lets you exclude up to $10M of gain on a future sale from federal tax. That single rule shifts exercise-timing math more than AMT does. (This is §1202 “qualified small-business stock”.) Modeled in beta, not here.
You solved the exercise window. The beta plans what comes after it: the new shares, your remaining equity, hedges, and taxes in one multi-year plan.
Request beta access →About Decagon
Decagon is a privately held AI company, incorporated in California and headquartered in San Francisco, CA.
$4.5B Series D.
Equity grants at Decagon typically include incentive stock options (ISOs) and non-qualified stock options (NSOs).
Decagon AI, Inc. is an American artificial intelligence company that develops conversational AI agents for customer service. The company is headquartered in San Francisco, California with additional offices in New York City and London.
Source: Wikipedia (CC BY-SA 4.0)
Founded in 2023 by Jesse Zhang and Ashwin Sreenivas, Decagon builds autonomous AI agents that handle enterprise customer support across voice, chat, email, and SMS. The San Francisco company counts Eventbrite, Substack, Rippling, Bilt, Webflow, Duolingo, Chime, and Oura among its customers, with deflection rates averaging near 70 percent. Andreessen Horowitz and Accel led a $35M Series A in 2024, followed by a $65M round and a $131M Series C at a $1.5B valuation in June 2025. A $250M Series D in January 2026 tripled the valuation to $4.5B.
Sources: decagon.ai · decagon.ai · businesswire.com
Equity comp at Decagon
- In March 2026, Decagon completed its first tender offer (a company-organized window where employees can sell some vested shares to outside buyers) at a $4.5 billion valuation. The offer was co-led by Series D investors including Coatue Management, Index Ventures, and Andreessen Horowitz, and was open to Decagon's 300-plus employees. The company's valuation tripled from $1.5 billion in June 2025 to $4.5 billion by January 2026, and the tender marked the first opportunity for early employees to convert some equity to cash.
- Recent share-sale events (industry term: tender offers):
- Mar 2026: $4.5B implied valuation, led by Coatue Management · decagon.ai
Sources: decagon.ai · techcrunch.com
Researched 2026-05-07.
OptionsAhoy is an independent tool and is not affiliated with, endorsed by, or sponsored by Decagon.
If you are leaving Decagon with vested incentive stock options (ISOs), most stock plans give you 90 days from departure to exercise or forfeit them. The calculator works at any valuation: enter your strike and the current 409A fair market value (FMV) or an expected exit price. It computes your window deadline, the alternative minimum tax (AMT) cost of exercising in full, and the partial-exercise share count that maximizes expected after-tax value.
All Decagon tools → · Use the generic Post-Termination ISO Exercise Calculator for any company.
Decagon equity questions
- I left Decagon. How long do I have to exercise my ISOs?
- Most stock plans give you 90 days from your departure date to exercise vested incentive stock options (ISOs); unexercised options are forfeited when the window closes. Tax law is slightly wider: ISO treatment requires you to have been an employee within 3 months of exercise (Internal Revenue Code Section 422(a)(2)), so options exercised under an employer-extended window are taxed as non-qualified stock options (NSOs). Check your grant agreement for Decagon's exact terms. The calculator above computes your deadline from your departure date, the alternative minimum tax (AMT) cost of exercising, and the share count that maximizes after-tax value.
- Does Decagon grant ISOs, NSOs, or RSUs?
- Equity compensation at Decagon typically takes the form of incentive stock options (ISOs) and non-qualified stock options (NSOs). Incentive stock options can trigger the alternative minimum tax (AMT) when you exercise.
- Are Decagon shares eligible for QSBS?
- They might be. Qualified small business stock (QSBS) under Internal Revenue Code Section 1202 can exclude federal tax on much of the gain when shares were acquired at original issuance from a C-corporation while its gross assets were under $50 million, and held at least five years. Whether your Decagon shares qualify turns on when you acquired them and the company's asset size at that time.
One piece of the puzzle.
OptionsAhoy plans your Decagon equity alongside hedging, vesting, and de-concentration, across bullish, neutral, and bearish market scenarios. Free during beta.